As a young man, Roy Hellenberg was shot at with rubber bullets, beaten with batons and locked in an out-of-town warehouse - purely because he was black in South Africa.
Today, as a history teacher, he tells pupils how the perpetrators of apartheid were merely displaying normal human behaviour.
"When society says you're a second-class citizen, you question your ability to stand in society as an equal person," he said. "The messages are subtle, but they're insistent. And they remain there. You have to unlearn them and learn new messages in the process.
"But apartheid damaged the psyche of the perpetrators as much as mine. People taught they are superior are just as damaged as people taught they're inferior."
Mr Hellenberg is one of 38 international delegates attending a five-day Holocaust seminar in London this week. "Facing history" aims to show how teachers can use the Holocaust to highlight the universal human traits that allow genocide to happen.
So tendencies to reduce others to a single identity, scapegoat them or remain apathetic to ongoing events are examined, then related to more recent genocides in countries such as Rwanda, Sudan and Cambodia, as well as sectarian violence in South Africa and Northern Ireland.
Michael McIntyre, UK co-ordinator for "Facing history", said: "People are blamed because of the histories they carry around with them. But these are behaviours that are human, that happen everywhere. It's just that in some places they've led to genocide, violence and unrest."
Mr Hellenberg knows this from personal experience. Born into a black township, he spent his childhood afraid to go beyond its confines, terrified of being seen in the wrong place. He participated in anti-apartheid protests, which regularly ended in police violence. Protesters were locked in a large warehouse and left to wait.
"You'd be left there without any idea what would happen next," he said. "That uncertainty was quite difficult to deal with."
Today, he works with white perpetrators of apartheid, speaking to pupils about their distinct experiences. "Obviously, you carry baggage with you," he said. "You're coming to terms with anger, resentment and shame. But that capacity for doing evil to other human beings is a universal one. And the capacity to do good and listen to others is also a common one."
Pain, he points out, is not unique to South Africa. This is the aim of the project: to use the Holocaust to highlight the collective experiences behind individual suffering.
Julie Taggart, a history and citizenship teacher from Northern Ireland, believes this can help pupils to deal with their own country's turbulent past. She was five years old when the Troubles broke out.
"We had bomb scares whenever we went into Belfast, with the Army on the street with guns," she said. "That was normality; that was normal life. Teachers are of a generation who lived through that, so we all have our own baggage. But we can teach about the Holocaust in a non-biased way. You use something outside your own field of reference, so you can see Northern Ireland within a global context."
For Claire Mullord, head of citizenship at Woolwich Polytechnic School in south-east London, meeting teachers with first-hand experience of sectarian violence emphasises the urgent relevance of history. "You can look back on the Holocaust and say, 'That was 60 years ago,'" she said. "But it happened again in our lifetime. That makes you think about the world in quite a different way."
She plans to use the Holocaust to address the experiences of her Rwandan and Afghan pupils. "We're giving children an awareness of where we're coming from, where we're going, where we are now," she said. "We're teaching them about the choices people make, but also the choices people don't make: the people who stood by and let things happen. It makes you realise the responsibility you have as a teacher."
Mr Hellenberg agrees. "We're providing an opportunity for honesty on a much deeper level, where understanding starts to dawn," he said. "It's everybody's responsibility to keep a watchful eye."
FACING UP TO HISTORY
'Facing history' was set up to show that history lessons can be about more than just the past.
The aim of the US-based project is to teach pupils the importance of tolerance and the risks of misunderstanding. Democracy, they are taught, is fragile.
The project provides resources, including an annual week-long seminar, online courses and full-day and after-school workshops.